Care
Button Polyps from the Zoanthus genus are very popular with marine aquarists, on account of their many attractive colour forms and ease of keeping. These zoanthid colonies are very common throughout various reef zones, and reproduce very quickly, forming beautiful mats with individual polyps-tightly pressed together. Unlike some of the other zoanthids, these polyps do not incorporate sediments into their bases to reinforce their tissues, as seen in members of the Palythoa genus. Although accurate identification of the 60+ zoanthid species currently known is a minefield, these particular ButtonPolyps do have a divided sphincter muscle surrounding the oral opening, distinguishing anatomical characteristics of the genus that are useful for scientists. Button Polyps are easy to keep and soon spread across the rock work to create an impressive "living carpet", making them an excellent choice for beginners and seasoned aquarists alike. Despite their reputation for hardiness, they will still obviously require suitable water quality to thrive and to prevent overgrowth from filamentous algae, which can swamp them if it is allowed to get out of hand. Placing the colony in an area that receives a moderate, but not overpowering, flow of water is also beneficial to stop the build-up of detritus. Lighting should be bright to allow the symbiotic zooxanthellae within the tissues of the polyps to flourish, although Button Polyps tend to be a little more forgiving about light intensity compared to other corals, largely because they also take microscopic foods from the water column. Once settled into a stable environment, Zoanthusspp. will spread rapidly across the décor, so do leave plenty of room for the colony to expand. Reef fish and most predatory invertebrates tend to leave zoanthids alone due to their toxic nature, although there are one or two exceptions that will try their luck. The exact potency level of the palytoxin varies from one zoanthid to another, but it must be stressed that this particular toxin is extremely powerful and aquarists must take sensible precautions when handling these animals. Despite the potent chemical defences, there are a handful of pests that may try and predate on your zoanthids, such as Camelback Shrimp (Rhynchocinetes uritai), shrimps from the genera Saron and Lysmata, Sundial Snails (Heliacusvariegatus), eunicid worms, certain nudibranch species, and Zoanthus-eating spiders. It is a good idea to quarantine new Zoanthuspolyps for several weeks before adding them to the main aquarium, to lessen the chance of introducing any destructive pests. If this is not an option then a 3-minute R/O freshwater dip can sometimes be useful before adding new polyps to the display tank, although it will not be as effective as a period of quarantine and careful observation. Button Polyps are available in a huge number of colours, from brown, green, blue-green, and orange, with contrasting colours on oral disks and tentacles, and all will fluoresce brilliantly in the evening. Some brightly coloured specimens even have wild-sounding common names such as "Dragon Eye", "Eagle Eye", "Hypercolour", "Mean Green", "Mind Bender", "Starfire", "Sunrise Supernova" and more.
Feeding
Zoanthus spp. are zooxanthellate; that is they usually get most of their nutrition from their symbiotic algae. However, they also take particulate foods from the water column, such as zooplankton, copepods, Artemianauplii etc.
Propagation
Easy to propagate - Zoanthus spp. reproduce readily by buds that are attached at their base to the parent colony. We do not recommend fragging, as this exposes the aquarist to a very real danger from palytoxin "instead just let the colony grow over onto small pieces of adjacent rockwork if you wish to propagate further colonies.
